Each streaming service has their own exclusive deals with publishers and offer a completely different catalog of music/movies.
This is why pirate sites are far superior, because they don't have those artificial limits on the product catalog offered.
What? If a piece of music is on one streaming service, it's on all of them.
In the US, this song is unavailable on Spotify where I found it, but available on YT music. Preface by Man Without Country. Given another 5 minutes, I could also find a song that is not listed on one but available on another.
https://music.you tube.com/watch?v=bvWjybBBFYs
The ones that aren’t available on Spotify tend to be self-released but otherwise there isn’t much of a pattern. Albums not on Bandcamp, though, tend to be mediocre at best.
And that’s not even mentioning bands that are pulling their music from Spotify in protest…
"Piracy is a service problem" -- Gabe Newell
But the video streaming platforms haven't gotten that memo yet and prefer to dig themselves into a larger and larger hole, both as far as normal Netflix style on-demand streaming, and IPTV style streams for sports and such. Hence why piracy of both are growing, with torrents on one side and IPTV pirate streams on the other.
Even the big unions have failed to put an end to this unholy mess.
My GF's Spotify makes great playlists, but they deleted my account twice and I'd never go back. So in that sense I'm willing to pay extra for customer service, which many of them don't care for. That's an interesting differentiator.